Low Birth Weight Across Generations

早期的研究描述了母亲和婴儿出生体重之间的相关性。对包括身长和头围在内的其他胎儿生长参数的研究表明，低出生体重母亲的婴儿比出生体重较大的母亲的婴儿更矮、更轻，但婴儿的比例正常。在随后的研究中，田纳西州1979至1984年间出生的婴儿的出生证明与其母亲的出生证明相匹配，后者在1959至1966年间出生。母亲和婴儿的出生体重再次被证明是相关的。此外，出生体重低的女性生下小于胎龄儿的可能性是出生时体重在4000-4499克之间的女性的四倍，但出生体重低的女性早产的可能性不到两倍。接下来研究的是一群出生于1955至1965年间的瑞典女性。出生时小于胎龄的妇女生下小于胎龄和早产儿的风险增加。出生时早产的女性患这两种结果的风险都不会增加。在丹麦围产期研究(1959-61年)中出生的妇女中，出生SGA的妇女生下SGA的风险增加了一倍，但早产的妇女生下早产的风险并没有增加。此外，出生时小于胎龄的妇女在怀孕期间患高血压的风险更高。与母亲出生时的大小无关，出生时父亲的大小被发现与胎儿生长有关，但与妊娠持续时间无关。在费城和普罗维登斯合作围产期项目的队列中，出生于1959-66年间的女孩在成年后接受了跟踪调查，并确定了她们的妊娠结局。这些妇女的数据分析目前正在进行中。初步分析评估了母亲的出生特征和年长的兄弟姐妹的出生特征对最小的兄弟姐妹的出生特征的相对贡献。母亲在出生时的SGA状态和年长兄弟姐妹的SGA状态都可以预测最小的兄弟姐妹的SGA状态。虽然有一个早产的大兄弟姐妹预示着最小的兄弟姐妹早产(优势比=5.5)，但有一个早产母亲不会(优势比=1.0)。母亲和大龄同胞出生特征之间没有交互作用。

Early work described the correlation between birthweights of mothers and their infants. The study of other fetal growth parameters, including length and head circumference demonstrated that infants of low birth weight mothers were both shorter and lighter than infants of larger mothers, but that the infants were normally proportioned. In ensuing studies, birth certificates of infants born in Tennessee between 1979 to 1984 were matched with those of their mothers, who were born in Tennessee between 1959 to 1966. Maternal and infant birth weights were again shown to be correlated. In addition, women who were themselves of low birth weight were up to four times as likely to have a small-for-gestational age infant as were women who weighed 4000-4499 grams at birth, but low birth weight women were less than twice as likely to have a preterm infant. A group of Swedish women, born from 1955 to 1965, was next studied. Women who themselves were small-for gestational age at birth were at increased risk of giving birth to both small-for-gestational age and preterm infants. Women who were preterm at birth were not at increased risk of either outcome. Among women born in the Danish Perinatal Study (1959-61), women born SGA were found to be at doubled risk of having an SGA child, but women born preterm were not at increased risk of giving birth to a preterm child. In addition, women who were small-for-gestational age at birth were at increased risk of developing hypertension during pregnancy. Independent of maternal size at birth, paternal size at birth was found to be associated with fetal growth, but not with duration of gestation. Girls who were born from 1959-66 as subjects in the Philadelphia and Providence cohorts of the Collaborative Perinatal Project were followed-up in adulthood, and their pregnancy outcomes ascertained. Data analysis from these women is currently underway. Initial analyses evaluated the relative contributions of the birth characteristics of the mother and those of older siblings on the birth characteristics of the youngest sibling. Both the mother's own SGA status at birth, and the SGA status of older siblings each predicted SGA status of the youngest sibling. Although having a preterm older sibling predicted preterm birth in the youngest sibling (odds ratio=5.5), having a preterm mother did not (odds ratio=1.0). There were no interactions between maternal and older sib birth characteristics.